Keywords

Ventricular septal defect. Congenital heart disease.

Abstract

We present an alternative technique for closing multiple ventricular septal defects difficult to access during surgery. A guidewire is advanced through the right ventricular free wall and through the main apical defect to the left ventricle, and this approach is used to place an Amplatzer device to occlude the ventricular septal defects. The procedure is performed in the beating heart, under intraoperative transesophageal echocardiographic guidance, and without extracorporeal circulation. It appears to be a simple and reproducible procedure with excellent short-term results.

Article

INTRODUCTION

Surgical treatment of multiple ventricular septal defects (VSDs) is
complex, particularly with anterior and apical locations. Normally,
several interventions are required, increasing the risk of adverse
effects and death unrelated to the residual shunts. There is also a
greater need for ventriculotomies and extensive sectioning to
facilitate access. Percutaneous approach is also difficult,
particularly in small children who have limited vascular access and
may poorly tolerate the use of large devices. Percutaneous device
placement under direct vision with extracorporeal circulation (ECC)
and cardioplegia have not produced outstanding results.1
Amin et al2 reported perventricular closure with an
Amplatzer device (AGA Medical Corporation, MN, United States of
America) for VSD occlusion. The technique was updated by Bacha et
al3 with excellent results in the first consecutive
series of patients studied. The self-expandable double-disk device
is made from nitinol mesh with the disks joined by a 7 mm waist.
The diameter of the disks determines the size of the Amplatzer
device.

CASE
STUDY

A
15-month-old girl weighing 8 kg with multiple VSDs (large posterior
muscular VSD and apical "Swiss cheese" septal defects) had received
a pulmonary artery (PA) band during the neonatal period. One year
later, definitive corrective surgery was planned. The
echocardiogram revealed a posterior muscular defect and three other
apical defects measuring 3 mm to 6 mm. These apical defects were
the only defect on the left side of the septum. The PA band was
correctly positioned, with a gradient of 80 mm Hg. Moderate right
ventricular (RV) hypertrophy was apparent.

Informed consent was obtained before implanting the Amplatzer
device.

After medial sternotomy, the heart and great vessels were exposed.
Under transesophageal echocardiographic (TEE) guidance with the
heart beating, the RV free wall was punctured with an 18 G needle,
avoiding the papillary muscles. An ultraflexible guidewire was
introduced into the left ventricle (LV) through the largest apical
defect (Figure 1A). An 8 F sheaf was then introduced into the LV
over the guidewire, which was subsequently retracted (Figure 1B).
The size of the device had to be 1 to 2 mm larger than the main
VSD, thus an 8 mm Amplatzer device was chosen. After immersion in
unheparinized blood for 20 minutes to allow the pores in the
nitinol mesh to become blocked, the device was screwed onto the
release system (cable). A 7 F sheaf was introduced under watertight
seal, and advanced over the introducer. The sheaf was then tensed
to allow deployment of the left disk (Figure 1C). The whole system
was then tensed (cable and sheaf) so that the disk lay against the
septum (Figure 1D). Then the other sheaf was withdrawn and the
right disk was deployed. Monitoring with TEE showed that there was
no residual shunting and that the disks were correctly positioned
(Figure 2). The cable was then unscrewed and the device released
(Figure 1E). The RV puncture site was repaired and we proceeded to
conventional closure of the posterior muscular VSD with a synthetic
patch. Finally, with ECC and aortic clamps in place, the AP band
was withdrawn.

Figure 1. Schematic representation of perventricular closure of
a ventricular septal defect with an Amplatzer device.

The
patient recovered with no evidence of ventricular dysfunction or
arrhythmias. Chest x-ray showed that the device and the disks were
correctly deployed (Figure 3) and the echocardiogram before
discharge from hospital showed no residual shunt. The girl was
discharged after 5 days and remains well after 6 months of
follow-up.

Despite progress in surgery, repair of certain types of VSD remains
a challenge, even in hospitals with extensive
experience.4,5

The
technique we describe is reproducible and appears to be a promising
alternative for patients with multiple VSDs, particularly with
apical or anterior locations where access is difficult. It might
also be an option in patients who have difficult vascular access
but who are nevertheless candidates for percutaneous closure of
VSD. Finally, it could be an interesting alternative for patients
who require surgery for complex heart disease and who also have
VSDs. This technique shortens ECC time and, more importantly,
aortic clamping time, and so it represents an advance with respect
to device placement techniques under direct vision. Despite the
limited experience with this technique, the results are promising
and it could become a treatment of choice.